1. Field of the Invention
The present invention relates to a technique for detecting a vehicular collision.
2. Description of the Related Art
In prior art, a variety of vehicle impact sensors configured to detect the occurrence of a collision at the time of a vehicular accident are known. For example, in JP, A, 2007-71596, there is disclosed a technique for detecting the collision particulars of a vehicle using a pressure sensor. This pressure sensor disclosed in JP, A, 2007-71596, is arranged in a vehicle door cavity formed between a door outer panel and a door inner panel of the vehicle door, and detects the change in pressure within this door cavity. The difficulty in achieving a high level of airtightness within the door cavity partitioned by the door outer panel and the door inner panel, however, results in limited appropriate association of the pressure fluctuation within the door cavity and the collision particulars of the vehicle. In particular, in the event of a collision resulting in a large amount of vehicle deformation despite a low collision velocity, such as a pole collision in which the vehicle collides with a pole-like collision object, the time rate of change of pressure is small, resulting in the problem that the detection accuracy achieved by the pressure sensor decreases considerably when the airtightness of the door cavity is low.